M. Muijtjens (Manja)http://repub.eur.nl/ppl/88/
List of Publicationsenhttp://repub.eur.nl/eur_signature.pnghttp://repub.eur.nl/
RePub, Erasmus University RepositoryThe structure-specific endonuclease Ercc1-Xpf is required for targeted gene replacement in embryonic stem cellshttp://repub.eur.nl/pub/66861/
Thu, 15 Nov 2001 00:00:01 GMT<div>L.J. Niedernhofer</div><div>J. Essers</div><div>G. Weeda</div><div>H.B. Beverloo</div><div>J. de Wit</div><div>M. Muijtjens</div><div>H. Odijk</div><div>J.H.J. Hoeijmakers</div><div>R. Kanaar</div>
Targeted disruption of the cell-cycle checkpoint gene ATR leads to early embryonic lethality in micehttp://repub.eur.nl/pub/58745/
Sat, 01 Apr 2000 00:00:01 GMT<div>J.E.M.M. de Klein</div><div>M. Muijtjens</div><div>R.I. van Os</div><div>Y. Verhoeven</div><div>B. Smit</div><div>A.M. Carr</div><div>A.R. Lehmann</div><div>J.H.J. Hoeijmakers</div>
Photic induction of mPer1 and mPer2 in cry-deficient mice lacking a biological clockhttp://repub.eur.nl/pub/56215/
Fri, 24 Dec 1999 00:00:01 GMT<div>H. Okamura</div><div>S. Miyake</div><div>Y. Sumi</div><div>S. Yamaguchi</div><div>A. Yasui</div><div>M. Muijtjens</div><div>J.H.J. Hoeijmakers</div><div>G.T.J. van der Horst</div>
MammalianCry1 and Cry2 are essential for maintenance of circadian rhythmshttp://repub.eur.nl/pub/3159/
Thu, 15 Apr 1999 00:00:01 GMT<div>G.T.J. van der Horst</div><div>M. Muijtjens</div><div>K. Kobayashi</div><div>R. Takano</div><div>S-I. Kanno</div><div>M. Takao</div><div>J. de Wit</div><div>A. Verkerk</div><div>A.P.M. Eker</div><div>D. van Leenen</div><div>R. Buijs</div><div>D. Bootsma</div><div>J.H.J. Hoeijmakers</div><div>A. Yasui</div>
Many biochemical, physiological and behavioural processes show circadian rhythms which are generated by an internal time-keeping mechanism referred to as the biological clock. According to rapidly developing models, the core oscillator driving this clock is composed of an autoregulatory transcription-(post) translation-based feedback loop involving a set of 'dock' genes. Molecular clocks do not oscillate with an exact 24-hour rhythmicity but are entrained to solar day/night rhythms by light. The mammalian proteins Cryl and Cry2, which are members of the family of plant blue-light receptors (cryptochromes) and photolyases, have been proposed as candidate light receptors for photoentrainment of the biological clock. Here we show that mice lacking the Cryl or Cry2 protein display accelerated and delayed free-running periodicity of locomotor activity, respectively. Strikingly, in the absence of both proteins, an instantaneous and complete loss of free-running rhythmicity is observed. This suggests that, in addition to a possible photoreceptor and antagonistic clock-adjusting function, both proteins are essential for the maintenance of circadian rhythmicity.A G→A transition creates a branch point sequence and activation of a cryptic exon, resulting in the hereditary disorder neurofibromatosis 2http://repub.eur.nl/pub/58806/
Sun, 01 Mar 1998 00:00:01 GMT<div>J.E.M.M. de Klein</div><div>P.H.J. Riegman</div><div>E.K. Bijlsma</div><div>A. Heldoorn</div><div>M. Muijtjens</div><div>M.A. den Bakker</div><div>C.J.J. Avezaat</div><div>E.C. Zwarthoff</div>
A G-->A transition creates a branch point sequence and activation of a cryptic exon, resulting in the hereditary disorder neurofibromatosis 2http://repub.eur.nl/pub/8773/
Thu, 01 Jan 1998 00:00:01 GMT<div>J.E.M.M. de Klein</div><div>P.H.J. Riegman</div><div>E.K. Bijlsma</div><div>A. Heldoorn</div><div>M. Muijtjens</div><div>M.A. den Bakker</div><div>C.J.J. Avezaat</div><div>E.C. Zwarthoff</div>
We describe a G-->A transition within intron 5 of the NF2 gene. This
mutation creates a consensus splice branch point sequence. To our
knowledge this is the first report of a mutation that creates a functional
branch point sequence in a human hereditary disorder. The new branch point
sequence is located 18 bp upstream of a consensus splice acceptor site. A
consensus splice donor site is found 106 bp 3' of the acceptor site. Asa
consequence the G-->A transition results in an alternatively spliced mRNA
containing an additional exon 5a of 106 bp derived from intron sequences.
We cloned the mutant cDNA and show that due to an in-frame stop codon the
cDNA codes for a truncated NF2 protein. The mutation was observed in three
affected members of an NF2 family. In a tumour of one of the family
members both alternatively spliced and wild-type mRNA were found, although
the wild-type allele of the gene is absent due to an interstitial deletion
on chromosome 22. We also show that immunoprecipitations reveal the
presence of full-length wild-type NF2 protein in the tumour lysate. These
data support the hypothesis that some degree of normal splicing of the
mutant precursor RNA is taking place. It is therefore likely that this
residual activity of the mutant allele explains the relatively mild
phenotype in the family. These data also indicate that complete
inactivation of the gene is not required for tumour formation.